Wipers are commonly used articles for cleaning surfaces, personal hygiene, and absorbing liquids, greases, oils or other similar substances. Such wipers are generally produced in a myriad of well known ways. Wipers can be made by woven, knitted, wet-formed, dry-formed, and nonwoven manufacturing processes to name only a few. Materials such as cellulose and other natural fibers in addition to polymeric and other synthetic substances are often used individually or in combination to produce most common wipers.
Some such wipers have the additional utility of substances added to the wiper. Wipers are available with disinfectants, sanitizers, cleaning solutions, soaps, medicines, emollients, beauty aids, fragrances, and other such substances. Many of such wipers are delivered to the user in a wet form where the substance is saturated into the wiper or is applied to the surface of the wiper in a wet form. An example of such a wiper can be found in U.S. Pat. No. 4,904,524 to Yoh. Another common example are cleansing wet wipes which are often dispensed from a sealable, moisture-proof package or tub, or in a single wipe foil-lined pouch. Sealable, moisture-proof packaging is required for such wet wipes to keep the wipes from drying out through evaporation of the liquid medium and to aid in the transport of the wet wipe.
Other wipers provide the utility of additional substances in a dry wiper form. Often these substances are encapsulated and applied to the surface of the wiper or impregnated into the fibrous structure of the wiper, or they are encapsulated by pockets formed by, or in, the layers of a laminate wiper structure. For example, U.S. Pat. No. Re 32,713 to Woo (Original U.S. Pat. No. 4,514,461) teaches an encapsulated fragrance that is applied to the surface of the fabric or is impregnated within the interstices of the fibers of the fabric. Examples of a substance encapsulated by the layers of the laminate structure of the wiper can be found in U.S. Pat. No. 4,259,383 Eggensperger et al.; U.S. Pat. No. 4,515,703 to Haq; and U.S. Pat. No. 4,600,620 to Lloyd et al.; as well as in U.S. Patent Publication 2002/0039867 to Curro et al.
The functional substance that is contained in these wipers is released in a number of ways. First, for the wipes that are delivered in the wet form, the wipes are generally ready for use when removed from their packages. In some instances the stresses of dispensing can release encapsulated materials that have been additionally included, as U.S. Pat. No. 4,904,524 indicates. However, such wet wipes often require cumbersome packaging and if such packaging is not sealed properly may result in dried-up and useless wipes.
Wipes that are delivered in a dry state generally release the active ingredient by either the addition of a liquid or by the addition of pressure. U.S. Pat. No. 4,259,383 is an example of a disinfecting tissue where the active ingredient is activated when it is contacted with water. In U.S. Pat. Nos. 4,600,620 and 4,515,703 and U.S. Patent Publication 2002/0039867 all have an active agent encapsulated within the layers of their respective laminate structures. In these cases, the active agent is released when pressure is applied to the laminate structure. The agent is released through weakened bonds in the substrate or through perforations.